Commutator tester



July 25, 1950 o. H. BUTLER COMMUTATOR TESTER 2 Sheets-Sheet 1 Filed Aug. 22, 1946 ....1 l III Af, Ellliicnfif: d@

INVENTOR. 0 55 HuZer.

July 25, 1950 o. H. BUTLER 2,516,615

COMMUTATOR TESTER Filed Aug. 22, 1946 2 Sheets-Sheet 2 IN VEN TOR.

ATTD R N EYB Patented `Iuly 25, `195i)- UNITED STATES PATENT OFFICE COMMUTAfroR TESTER ons H. Butler, 1265 Angeles, Calif.

'application August 22, 1946, serial No. 692,360

My present invention relates to an :improved commutator tester and more particularly to the type of device or apparatus of simple assembly and wherein the use thereof enables the operator to determine with facility and dispatch f whether a commutator is cleared of all shorts in its electrical set-up, thereby avoiding the placement of a shorted commutator on an armature 1with the attendant waste of labor and loss of une.

In the accompanying drawings I have illustrated one complete example of the physical embodiment of my invention according to the best mode I have thus far devised but it will be under'- stood that various changes and alterations may be made in the exemplified structure within the scope of the appended claim.

In the drawing:

Figure l is a top plan vieur of the apparatus of my invention.

Figure 2 is a diagrammatic view of the electrical circuit therefore.

Figure 3 is a side elevational view of the device of my invention.

Figure 4 is a perspective view of one of the adjustable contacts of the device.

Figure 5 is an elevational view of a phone jack employed in the operation of my invention.

Figure 6 is a longitudinal sectional view through the jack.

Figure '7 is a vertical sectional View through the device.

Figure 8 is a view similar to Figure '7 and taken at substantially right angles thereto.

Referring now to the drawings in detail wherein like characters indicate like parts I have illustrated the present embodiment of my invention as including in the general construction, an undercut body forming a base or bed IB. of suitable size and shape and made of insulating material.

In the present embodiment, the base or bed Iii is substantially square in formation, and has superimposed on its top face an upstanding block bearing II, also of insulating material, and secured by fasteners I2 to the base or bed, the said bearing being formed with a transverse socket in which is threaded a coupling sleeve I3 into which is detachably tapped a supporting shaft I4, which may be of a selected size in length and diameter.

for supporting a commutator generally denoted as I5, according to its size, for testing purposes.

At one side of the point of location of the shaft I4 and upon the base or bed II! I employ a pair of spaced adjustable resilient steel contact arms 1 Claim. (Cl. 175-183) I5, each at its attaching end being formed with an elongated slot I'I for 'adjustment on a connecter I8, fitted in the bed or base, and these Contact arms are in an electric circuit I9, which has arranged 'therein' the electricfsignal lamps 2t and 2|, and a transformer 22. The sleeve I3 is held by a binding screw 23, which has electrical connection with a circuit by a wiring 24, while leading to the transformer is an electric extension cord 25 for connection with a current supply, not shown.

Arranged in the base or bed Ill is a pair of conventional radio phone jacks 25 in which are detachably engageable connectors 9 for conventional radio test prods 21, for use in testing the commutator for grounds from any bar of the commutator to shaft I4 or between any bars not reached by the arms I6, and also when the com'- mutator has been removed from the said shaft I4 and installed in a set-up therefor. The prods 2l are adjustably tted to an insulated handle grip 28 as best seen in Figures 5 and 6 of the drawings.

The prods 2'I are adjustable in the handle grip 28 for lengthening or shortening thereof, or for properly contacting selected bars of the commutator. These prods 21 are used independently of the arms I6, as will be described.

The jacks 26 are in electrical connection with the circuit I9, and the prods 2'I have detachable couplings 9 with the sockets.

The testing device or apparatus of my invention is used as described for testing commutator or armatures to determine if any of the copper bars of the commutator are shorted to each other, or to the sleeve of the commutator through which the armature shaft is forced.

In such use the commutator I5 is placed on the shaft I4 While lifting the arms I6, the commutator being received by the shaft I4, and the arms making contact with the copper bars of the commutator. If any two bars are shorted together, the current will flow through said arms and the lamp 2l) will be illuminated. If the lamp 2| is illuminated then the bar, upon which the contact arm rests is grounded to the shaft I4 as the current flows from the contact arm through the bar tothe shaft through lamp 20. One contact arm is common to both tests, and the jacks are provided so that a test can be made on an armature after the commutator is placed in position and connected, or a test may be made on an armature and commutator without removing the commutator from the armature.

Having thus fully described my invention what I claim as new and desire to secure by Letters Patent is:

In a commutator bar tester, the combination which comprises a base having a flat upper sur-- face, a bearing block of insulating material mounted on and extended upwardly from the said base, a horizontally disposed commutator bar mounting shaft spaced above the upper surface of the base and mounted, through one end thereof, in said bearing block with the opposite end extended outwardly therefrom, a pair of clip angles with slotted bases adjustably mounted through the slots thereof on said base and positioned laterally of said shaft, upwardly extended-f contact arms with arcuate upper ends carried by said clip angles and positioned to engage segments or bars of a commutator positioned* on the said shaft, one of said contact arms being longer than the other whereby with the end' of' one arm engaging a segment of a commutator bar the endV of the other arm is'in engagementy with' the adjoining segment, said contact arms being insulated from the base, a pair of signal lamps positionedl on said'. base, a pair of radio phone jacks positioned on the base, a circuit connect- 4 I ing the signal lamps, phone jacks and contact arms whereby with the contact arms engaging adjoining commutator bars a circuit is complete to one of the signal lights and with the radio phone jacks connected to the shaft and to a commutator bar a short or ground in the commutator completes a circuit to the other signal light, and an electric cord extended from said base for supplying current to the said circuit of the elements thereon.

OTIS" H. BUTLER.

REFERENCES CITED The. following references are of record in the -le of. this patent:

UNITED STATES PATENTS Number Name Date 1,372,945 Cullin Mar. 29, 1921 1,412,051 Gaalaas Apr. 11, 1922 1,432,003 West' Oct. 17, 1922 1,479,284 Cullin Jan. 1, 19211 1,537,490 Oman May12, 1925 1,971,426 Poole Aug. 28, 1934 

